<!--[if gte mso 10]> Agar and Carrageenan Think about the chemical structure of carrageenan and agar - what do they have in common?
Agar = Ø Extracted from seaweed and is used in many foods as a gelling agent. Ø Agar is a polymer of agarobiose, a disaccharide composed of D-galactose and 3,6-anhydro-L-galactose. Ø Highly refined agar is used as a medium for culturing bacteria, cellular tissues, and for DNA fingerprinting. Ø used as =
-An ingredient in desserts in Japan and other Asian countries. The gels produced with agar have a crispier texture than the desserts made with animal gelatin.
Carrageenan = Ø A generic term for several polysaccharides also extracted from seaweed. Ø Carrageenan compounds differ from agar in that they have sulfate groups (-OSO3-) in place of some hydroxyl groups.
- carrageenan structure is composed of linear galactan polysaccharides that have a sulfate content of 15%-40%. Ø used as =
-Thickening, suspending, and gelling food products. What are the differences between kappa, iota and lambda carrageenan? Why? There are 3 types of carrageenan :
Kappa
Lambda
Iota
Types of carrageenan
Kappa
Lambda
Iota
Repeating Unit
D-Galactose-4-Sulphate linked with
3,6-anhydrous-D-Galactose
D-Galactose-4-Sulphate linked with
3,6-Galactose-2-Sulphate
D-Galactose-2-Sulphate and
D-Galactose-2,6-Disulphate
Sulphate content
~25%
~32%
~35%
Kappa-carrageenan is mostly the alternating polymer of D-galactose-4-sulfate and 3,6-anhydro-D-galactose.Iota-carrageenan is similar,except that the 3,6-anhydrogalactose is sulfated at carbon 2.
Between kappa-carrageenan and iota-carrageenan there is a continuum of intermediate compositions differing in degree of sulfation at carbon 2.
In lambda-carrageenan,the alternating monomeric units are mostly D-galactose-2-sulfate (1,3-linked)and D-galactose-2,6-disulfate (1,4-linked).
Agar and Carrageenan
Think about the chemical structure of carrageenan and agar - what do they have in common?
Agar =
Ø Extracted from seaweed and is used in many foods as a gelling agent.
Ø Agar is a polymer of agarobiose, a disaccharide composed of D-galactose and 3,6-anhydro-L-galactose.
Ø Highly refined agar is used as a medium for culturing bacteria, cellular tissues, and for DNA fingerprinting.
Ø used as =
-An ingredient in desserts in Japan and other Asian countries. The gels produced with agar have a crispier texture than the desserts made with animal gelatin.
Carrageenan =
Ø A generic term for several polysaccharides also extracted from seaweed.
Ø Carrageenan compounds differ from agar in that they have sulfate groups (-OSO3-) in place of some hydroxyl groups.
- carrageenan structure is composed of linear galactan polysaccharides that have a sulfate content of 15%-40%.
Ø used as =
-Thickening, suspending, and gelling food products.
What are the differences between kappa, iota and lambda carrageenan? Why?
There are 3 types of carrageenan :
3,6-anhydrous-D-Galactose
3,6-Galactose-2-Sulphate
D-Galactose-2,6-Disulphate
Kappa-carrageenan is mostly the alternating polymer of D-galactose-4-sulfate and 3,6-anhydro-D-galactose.Iota-carrageenan is similar,except that the 3,6-anhydrogalactose is sulfated at carbon 2.
Between kappa-carrageenan and iota-carrageenan there is a continuum of intermediate compositions differing in degree of sulfation at carbon 2.
In lambda-carrageenan,the alternating monomeric units are mostly D-galactose-2-sulfate (1,3-linked)and D-galactose-2,6-disulfate (1,4-linked).